OVERALL GOALS OF THE TOTAL PROJECT: The fundamental objective of this research is to elucidate the mechanism(s) of control of several hepatic functions by cyclic AMP. Its overall goal is to achieve an understanding of the regulation of the functions of this tissue that occur in response to a number of hormones whose actions are mediated by this nucleotide. GOALS SET FOR CURRENT YEAR: 1) Examine the regulation of protein phosphorylation in perfused liver and heart response to glucagon and epinephrine as manifest by changes in the perfusion media i.e.: time of perfusion, glucagon concentrations, Ca2 ion concentrations, etc. 2) Investigateh the regulation of nuclear hepatic protein kinase by glucagon. 3) Examine the sites of action of cyclic AMP in liver as identified by the perfusion of H3 dbcAMP. BIBLIOGRAPHIC REFERENCES: Nuclear Protein Kinase Activity in Perfused Rat Liver Stimulated with Dibutyryl Adenosine-3' 5'-Cyclic Monophosphate. Castagna, M., Palmer, W.K. and Walsh, D.A. (1975). Eur. J. Biochem. 55, 193-199. The Modulation of Skeletal Muscle Glycogenolysis as a Model of Cyclic AMP Action. Walsh, D.A. (1975) in Function Linkage in Biomolecular Systems. Raven Press, pp. 206-209.